The present invention relates to a nonrecorded section detecting system in a tape recorder apparatus.
In a conventional nonrecorded section detection system, a charge/discharge circuit is connected to receive an output signal of an amplifier associated with a reproduction head for charging it when the reproduction head contacts a recorded portion. When the charge level of the charge/discharge circuit becomes below a predetermined value after the reproduction head reaches the nonrecorded section, a tape feed mechanism is automatically shifted to its normal playback mode.
It is important in the above-mentioned nonrecorded section detection system of the prior art that the output level of the amplifier is considerably high to perform an accurate operation. Moreover, variations of the power supply voltage greatly influence the accuracy of the detection of the nonrecorded section in the prior art system.
Accordingly, an object of the present invention is to provide a nonrecorded section detection system for a tape recorder apparatus which ensures an accurate operation.
Another object of the present invention is to provide a nonrecorded section detection system for a tape recorder apparatus which can accurately detect the nonrecorded section even when the power supply voltage varies.
Other objects and further scope of applicability of the present invention will become apparent from the detailed description given hereinafter. It should be understood, however, that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.
To achieve the above objects, pursuant to an embodiment of the present invention, a switching transistor is connected to receive an output signal of an amplifier associated with a reproduction head when a nonrecorded section detection switch is depressed. A charge/discharge loop is connected to receive its charge current through the switching transistor when the reproduction head contacts a recorded section and, hence, the switching transistor is ON. When the charge level of the charge/discharge circuit becomes below a predetermined value after the reproduction head reaches the nonrecorded section, that is, the switching transistor becomes OFF, a tape feed mechanism is automatically shifted to its normal playback mode.